1. Field of the Invention
The invention relates to wellhead lubricators. In particular, the invention relates to wellhead lubricators connected to the top of a wellhead or "Christmas Tree."
2. Description of the Related Art
"Wellhead lubricators" and "wireline lubricators" are well known in the art. "Wellhead lubricators" and "wireline lubricators" are devices which are connected to the top of a wellhead of an oil and/or gas well, or to a Christmas Tree connected to an oil and/or gas well to receive a cylindrical wireline tool which is suspended from a wire and lowered into the well to perform such tasks as logging, perforation, and the like. The lubricators are used to seal the volume of the pipe in which the wireline and tool is inserted to counteract the pressure in the petroleum and/or gas well and prevent gas and/or oil from escaping around the wireline during wireline operations.
When a wireline lubricator is removed from a Christmas Tree, there is a leakage of oil from the lubricator onto the area around the Christmas Tree. The leakage of lubricant from the lubricator can cause damage to the environment. Furthermore, it is expensive and time consuming to remove the spilled lubricant from the area upon which it has leaked.
Exemplary of the patents of the related art are the following U.S. Patents: U.S. Pat. Nos. 1,369,913; 3,500,907; 3,556,209; 3,568,767; 3,924,686; 4,489,780; 4,658,894; 4,665,976; 4,716,962; 5,088,559; and 5,392,861.